diff --git a/src/EntityGraphQL/Schema/SchemaBuilder.cs b/src/EntityGraphQL/Schema/SchemaBuilder.cs
index 008469d5..217c1c4a 100644
--- a/src/EntityGraphQL/Schema/SchemaBuilder.cs
+++ b/src/EntityGraphQL/Schema/SchemaBuilder.cs
@@ -478,7 +478,7 @@ internal static (string name, string description) GetNameAndDescription(MemberIn
                     var fields = GetFieldsFromObject(propType, typeAdded, schema, options, isInputType);
                     typeAdded.AddFields(fields);
 
-                    if (options.AutoCreateInterfaceTypes)
+                    if (options.AutoCreateInterfaceTypes && !typeAdded.IsInput)
                     {
                         typeAdded.ImplementAllBaseTypes(true, true);
                     }